Retaining existing captions/keywords after upload?

Firstly, many thanks for this excellent resource. Despite having very little PHP knowledge the software is intuitive and easy to use. I have a had a rummage around the forum before posting this question and could not see that it has been addressed before.

I have an image library of about 12000 photographs all of which are captioned and keyworded which I am planning to migrate to my Piwigo library running on my own server.

I am uploading the images embedded with the data, but I cannot see it when it is in the Piwigo galleries, although I know it is being retained as I am able to view it when I download the same files from Piwigo.

Is there a plug in or fix that will enable me to see the embedded captions/keywords or will I have to embed them all over again?